X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/fe8ab488e9161c46dd9885d58fc52996dc0249ff..3903760236c30e3b5ace7a4eefac3a269d68957c:/bsd/kern/kern_cs.c diff --git a/bsd/kern/kern_cs.c b/bsd/kern/kern_cs.c index 66af46613..6ff8c458b 100644 --- a/bsd/kern/kern_cs.c +++ b/bsd/kern/kern_cs.c @@ -71,6 +71,8 @@ #include +#include + unsigned long cs_procs_killed = 0; unsigned long cs_procs_invalidated = 0; @@ -78,27 +80,29 @@ int cs_force_kill = 0; int cs_force_hard = 0; int cs_debug = 0; #if SECURE_KERNEL -const int cs_enforcement_enable=1; -const int cs_library_val_enable=1; -#else +const int cs_enforcement_enable = 1; +const int cs_library_val_enable = 1; +#else /* !SECURE_KERNEL */ +int cs_enforcement_panic=0; + #if CONFIG_ENFORCE_SIGNED_CODE -int cs_enforcement_enable=1; +#define DEFAULT_CS_ENFORCEMENT_ENABLE 1 #else -int cs_enforcement_enable=0; -#endif /* CONFIG_ENFORCE_SIGNED_CODE */ +#define DEFAULT_CS_ENFORCEMENT_ENABLE 0 +#endif +SECURITY_READ_ONLY_LATE(int) cs_enforcement_enable = DEFAULT_CS_ENFORCEMENT_ENABLE; #if CONFIG_ENFORCE_LIBRARY_VALIDATION -int cs_library_val_enable = 1; +#define DEFAULT_CS_LIBRARY_VA_ENABLE 1 #else -int cs_library_val_enable = 0; -#endif /* CONFIG_ENFORCE_LIBRARY_VALIDATION */ +#define DEFAULT_CS_LIBRARY_VA_ENABLE 0 +#endif +SECURITY_READ_ONLY_LATE(int) cs_library_val_enable = DEFAULT_CS_LIBRARY_VA_ENABLE; -int cs_enforcement_panic=0; -#endif /* SECURE_KERNEL */ +#endif /* !SECURE_KERNEL */ int cs_all_vnodes = 0; static lck_grp_t *cs_lockgrp; -static lck_rw_t * SigPUPLock; SYSCTL_INT(_vm, OID_AUTO, cs_force_kill, CTLFLAG_RW | CTLFLAG_LOCKED, &cs_force_kill, 0, ""); SYSCTL_INT(_vm, OID_AUTO, cs_force_hard, CTLFLAG_RW | CTLFLAG_LOCKED, &cs_force_hard, 0, ""); @@ -109,7 +113,11 @@ SYSCTL_INT(_vm, OID_AUTO, cs_all_vnodes, CTLFLAG_RW | CTLFLAG_LOCKED, &cs_all_vn #if !SECURE_KERNEL SYSCTL_INT(_vm, OID_AUTO, cs_enforcement, CTLFLAG_RW | CTLFLAG_LOCKED, &cs_enforcement_enable, 0, ""); SYSCTL_INT(_vm, OID_AUTO, cs_enforcement_panic, CTLFLAG_RW | CTLFLAG_LOCKED, &cs_enforcement_panic, 0, ""); + +#if !CONFIG_ENFORCE_LIBRARY_VALIDATION +SYSCTL_INT(_vm, OID_AUTO, cs_library_validation, CTLFLAG_RW | CTLFLAG_LOCKED, &cs_library_val_enable, 0, ""); #endif +#endif /* !SECURE_KERNEL */ int panic_on_cs_killed = 0; void @@ -133,10 +141,16 @@ cs_init(void) } PE_parse_boot_argn("cs_debug", &cs_debug, sizeof (cs_debug)); + +#if !CONFIG_ENFORCE_LIBRARY_VALIDATION + PE_parse_boot_argn("cs_library_val_enable", &cs_library_val_enable, + sizeof (cs_library_val_enable)); #endif +#endif /* !SECURE_KERNEL */ + lck_grp_attr_t *attr = lck_grp_attr_alloc_init(); cs_lockgrp = lck_grp_alloc_init("KERNCS", attr); - SigPUPLock = lck_rw_alloc_init(cs_lockgrp, NULL); + lck_grp_attr_free(attr); } int @@ -162,6 +176,10 @@ cs_allow_invalid(struct proc *p) p->p_pid); proc_lock(p); p->p_csflags &= ~(CS_KILL | CS_HARD); + if (p->p_csflags & CS_VALID) + { + p->p_csflags |= CS_DEBUGGED; + } proc_unlock(p); vm_map_switch_protect(get_task_map(p->task), FALSE); #endif @@ -169,8 +187,7 @@ cs_allow_invalid(struct proc *p) } int -cs_invalid_page( - addr64_t vaddr) +cs_invalid_page(addr64_t vaddr, boolean_t *cs_killed) { struct proc *p; int send_kill = 0, retval = 0, verbose = cs_debug; @@ -192,25 +209,12 @@ cs_invalid_page( /* CS_KILL triggers a kill signal, and no you can't have the page. Nothing else. */ if (p->p_csflags & CS_KILL) { - if (panic_on_cs_killed && - vaddr >= SHARED_REGION_BASE && - vaddr < SHARED_REGION_BASE + SHARED_REGION_SIZE) { - panic(" cs_invalid_page(va=0x%llx): killing p=%p\n", (uint64_t) vaddr, p); - } p->p_csflags |= CS_KILLED; cs_procs_killed++; send_kill = 1; retval = 1; } -#if __x86_64__ - if (panic_on_cs_killed && - vaddr >= SHARED_REGION_BASE && - vaddr < SHARED_REGION_BASE + SHARED_REGION_SIZE) { - panic(" cs_invalid_page(va=0x%llx): cs error p=%p\n", (uint64_t) vaddr, p); - } -#endif /* __x86_64__ */ - /* CS_HARD means fail the mapping operation so the process stays valid. */ if (p->p_csflags & CS_HARD) { retval = 1; @@ -231,8 +235,15 @@ cs_invalid_page( retval ? "denying" : "allowing (remove VALID)", send_kill ? " sending SIGKILL" : ""); - if (send_kill) - threadsignal(current_thread(), SIGKILL, EXC_BAD_ACCESS); + if (send_kill) { + /* We will set the exit reason for the thread later */ + threadsignal(current_thread(), SIGKILL, EXC_BAD_ACCESS, FALSE); + if (cs_killed) { + *cs_killed = TRUE; + } + } else if (cs_killed) { + *cs_killed = FALSE; + } return retval; @@ -258,300 +269,204 @@ cs_enforcement(struct proc *p) return 0; } -static struct { - struct cscsr_functions *funcs; - vm_map_offset_t csr_map_base; - vm_map_size_t csr_map_size; - int inuse; - int disabled; -} csr_state; - -SYSCTL_INT(_vm, OID_AUTO, sigpup_disable, CTLFLAG_RW | CTLFLAG_LOCKED, &csr_state.disabled, 0, ""); - -static int -vnsize(vfs_context_t vfs, vnode_t vp, uint64_t *size) +/* + * Returns whether a given process is still valid. + */ +int +cs_valid(struct proc *p) { - struct vnode_attr va; - int error; - VATTR_INIT(&va); - VATTR_WANTED(&va, va_data_size); + if (p == NULL) + p = current_proc(); + + if (p != NULL && (p->p_csflags & CS_VALID)) + return 1; - error = vnode_getattr(vp, &va, vfs); - if (error) - return error; - *size = va.va_data_size; return 0; } +/* + * Library validation functions + */ int -sigpup_install(user_addr_t argsp) +cs_require_lv(struct proc *p) { - struct sigpup_install_table args; - memory_object_control_t control; - kern_return_t result; - vfs_context_t vfs = NULL; - struct vnode_attr va; - vnode_t vp = NULL; - char *buf = NULL; - uint64_t size; - size_t len = 0; - int error = 0; - if (!cs_enforcement_enable || csr_state.funcs == NULL) - return ENOTSUP; - - lck_rw_lock_exclusive(SigPUPLock); - - if (kauth_cred_issuser(kauth_cred_get()) == 0) { - error = EPERM; - goto cleanup; - } - - if (cs_debug > 10) - printf("sigpup install\n"); - - if (csr_state.csr_map_base != 0 || csr_state.inuse) { - error = EPERM; - goto cleanup; - } - - if (USER_ADDR_NULL == argsp) { - error = EINVAL; - goto cleanup; - } - if ((error = copyin(argsp, &args, sizeof(args))) != 0) - goto cleanup; - - if (cs_debug > 10) - printf("sigpup install with args\n"); - - MALLOC(buf, char *, MAXPATHLEN, M_TEMP, M_WAITOK); - if (buf == NULL) { - error = ENOMEM; - goto cleanup; - } - if ((error = copyinstr((user_addr_t)args.path, buf, MAXPATHLEN, &len)) != 0) - goto cleanup; - - if ((vfs = vfs_context_create(NULL)) == NULL) { - error = ENOMEM; - goto cleanup; - } - - if ((error = vnode_lookup(buf, VNODE_LOOKUP_NOFOLLOW, &vp, vfs)) != 0) - goto cleanup; - - if (cs_debug > 10) - printf("sigpup found file: %s\n", buf); - - /* make sure vnode is on the process's root volume */ - if (rootvnode->v_mount != vp->v_mount) { - if (cs_debug) printf("sigpup csr no on root volume\n"); - error = EPERM; - goto cleanup; - } - - /* make sure vnode is owned by "root" */ - VATTR_INIT(&va); - VATTR_WANTED(&va, va_uid); - error = vnode_getattr(vp, &va, vfs); - if (error) - goto cleanup; - - if (va.va_uid != 0) { - if (cs_debug) printf("sigpup: csr file not owned by root\n"); - error = EPERM; - goto cleanup; - } - - error = vnsize(vfs, vp, &size); - if (error) - goto cleanup; - - control = ubc_getobject(vp, 0); - if (control == MEMORY_OBJECT_CONTROL_NULL) { - error = EINVAL; - goto cleanup; - } - - csr_state.csr_map_size = mach_vm_round_page(size); - - if (cs_debug > 10) - printf("mmap!\n"); - - result = vm_map_enter_mem_object_control(kernel_map, - &csr_state.csr_map_base, - csr_state.csr_map_size, - 0, VM_FLAGS_ANYWHERE, - control, 0 /* file offset */, - 0 /* cow */, - VM_PROT_READ, - VM_PROT_READ, - VM_INHERIT_DEFAULT); - if (result != KERN_SUCCESS) { - error = EINVAL; - goto cleanup; - } - - error = csr_state.funcs->csr_validate_header((const uint8_t *)csr_state.csr_map_base, - csr_state.csr_map_size); - if (error) { - if (cs_debug > 10) - printf("sigpup header invalid, dropping mapping"); - sigpup_drop(); - goto cleanup; - } - - if (cs_debug > 10) - printf("table loaded %ld bytes\n", (long)csr_state.csr_map_size); - -cleanup: - lck_rw_unlock_exclusive(SigPUPLock); - - if (buf) - FREE(buf, M_TEMP); - if (vp) - (void)vnode_put(vp); - if (vfs) - (void)vfs_context_rele(vfs); - - if (error) - printf("sigpup: load failed with error: %d\n", error); - + if (cs_library_val_enable) + return 1; - return error; + if (p == NULL) + p = current_proc(); + + if (p != NULL && (p->p_csflags & CS_REQUIRE_LV)) + return 1; + + return 0; } +/* + * added to allow system level library + * validation check at mac_cred_label_update_execve time + */ int -sigpup_drop(void) +cs_system_require_lv(void) { + return cs_library_val_enable ? 1 : 0; +} - if (kauth_cred_issuser(kauth_cred_get()) == 0) - return EPERM; - - lck_rw_lock_exclusive(SigPUPLock); - - if (csr_state.csr_map_base == 0 || csr_state.inuse) { - printf("failed to unload the sigpup database\n"); - lck_rw_unlock_exclusive(SigPUPLock); - return EINVAL; - } +/* + * Function: csblob_get_base_offset + * + * Description: This function returns the base offset into the Mach-O binary + * for a given blob. +*/ - if (cs_debug > 10) - printf("sigpup: unloading\n"); +off_t +csblob_get_base_offset(struct cs_blob *blob) +{ + return blob->csb_base_offset; +} - (void)mach_vm_deallocate(kernel_map, - csr_state.csr_map_base, csr_state.csr_map_size); +/* + * Function: csblob_get_size + * + * Description: This function returns the size of a given blob. +*/ - csr_state.csr_map_base = 0; - csr_state.csr_map_size = 0; +vm_size_t +csblob_get_size(struct cs_blob *blob) +{ + return blob->csb_mem_size; +} - lck_rw_unlock_exclusive(SigPUPLock); +/* + * Function: csblob_get_addr + * + * Description: This function returns the address of a given blob. +*/ - return 0; +vm_address_t +csblob_get_addr(struct cs_blob *blob) +{ + return blob->csb_mem_kaddr; } -void sigpup_attach_vnode(vnode_t); /* XXX */ +/* + * Function: csblob_get_platform_binary + * + * Description: This function returns true if the binary is + * in the trust cache. +*/ -void -sigpup_attach_vnode(vnode_t vp) +int +csblob_get_platform_binary(struct cs_blob *blob) { - const void *csblob; - size_t cslen; - - if (!cs_enforcement_enable || csr_state.funcs == NULL || csr_state.csr_map_base == 0 || csr_state.disabled) - return; + if (blob && blob->csb_platform_binary) + return 1; + return 0; +} - /* if the file is not on the root volumes or already been check, skip */ - if (vp->v_mount != rootvnode->v_mount || (vp->v_flag & VNOCS)) - return; +/* + * Function: csblob_get_flags + * + * Description: This function returns the flags for a given blob +*/ - csblob = csr_state.funcs->csr_find_file_codedirectory(vp, (const uint8_t *)csr_state.csr_map_base, - (size_t)csr_state.csr_map_size, &cslen); - if (csblob) { - ubc_cs_sigpup_add(vp, (vm_address_t)csblob, (vm_size_t)cslen); - csr_state.inuse = 1; - } - vp->v_flag |= VNOCS; +unsigned int +csblob_get_flags(struct cs_blob *blob) +{ + return blob->csb_flags; } -void -cs_register_cscsr(struct cscsr_functions *funcs) +/* + * Function: csproc_get_blob + * + * Description: This function returns the cs_blob + * for the process p + */ +struct cs_blob * +csproc_get_blob(struct proc *p) { - if (csr_state.funcs || funcs->csr_version < CSCSR_VERSION) - return; - csr_state.funcs = funcs; + if (NULL == p) + return NULL; + + if (NULL == p->p_textvp) + return NULL; + + return ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff); } /* - * Library validation functions + * Function: csproc_get_blob + * + * Description: This function returns the cs_blob + * for the vnode vp */ -int -cs_require_lv(struct proc *p) +struct cs_blob * +csvnode_get_blob(struct vnode *vp, off_t offset) { - - if (cs_library_val_enable) - return 1; - - if (p == NULL) - p = current_proc(); - - if (p != NULL && (p->p_csflags & CS_REQUIRE_LV)) - return 1; - - return 0; + return ubc_cs_blob_get(vp, -1, offset); } /* * Function: csblob_get_teamid * - * Description: This function returns a pointer to the team id - stored within the codedirectory of the csblob. - If the codedirectory predates team-ids, it returns - NULL. - This does not copy the name but returns a pointer to - it within the CD. Subsequently, the CD must be - available when this is used. + * Description: This function returns a pointer to the + * team id of csblob */ const char * csblob_get_teamid(struct cs_blob *csblob) +{ + return csblob->csb_teamid; +} + +/* + * Function: csblob_get_identity + * + * Description: This function returns a pointer to the + * identity string + */ +const char * +csblob_get_identity(struct cs_blob *csblob) { const CS_CodeDirectory *cd; - if ((cd = (const CS_CodeDirectory *)cs_find_blob( - csblob, CSSLOT_CODEDIRECTORY, CSMAGIC_CODEDIRECTORY)) == NULL) - return NULL; - - if (ntohl(cd->version) < CS_SUPPORTSTEAMID) + cd = (const CS_CodeDirectory *)csblob_find_blob(csblob, CSSLOT_CODEDIRECTORY, CSMAGIC_CODEDIRECTORY); + if (cd == NULL) return NULL; - if (ntohl(cd->teamOffset) == 0) + if (cd->identOffset == 0) return NULL; - - const char *name = ((const char *)cd) + ntohl(cd->teamOffset); - if (cs_debug > 1) - printf("found team-id %s in cdblob\n", name); - return name; + return ((const char *)cd) + ntohl(cd->identOffset); } /* - * Function: csproc_get_blob + * Function: csblob_get_cdhash * - * Description: This function returns the cs_blob - * for the process p + * Description: This function returns a pointer to the + * cdhash of csblob (20 byte array) */ -static struct cs_blob * -csproc_get_blob(struct proc *p) +const uint8_t * +csblob_get_cdhash(struct cs_blob *csblob) { - if (NULL == p) - return NULL; + return csblob->csb_cdhash; +} - if (NULL == p->p_textvp) - return NULL; +void * +csblob_entitlements_dictionary_copy(struct cs_blob *csblob) +{ + if (!csblob->csb_entitlements) return NULL; + osobject_retain(csblob->csb_entitlements); + return csblob->csb_entitlements; +} - return ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff); +void +csblob_entitlements_dictionary_set(struct cs_blob *csblob, void * entitlements) +{ + assert(csblob->csb_entitlements == NULL); + if (entitlements) osobject_retain(entitlements); + csblob->csb_entitlements = entitlements; } /* @@ -566,8 +481,10 @@ csproc_get_teamid(struct proc *p) struct cs_blob *csblob; csblob = csproc_get_blob(p); + if (csblob == NULL) + return NULL; - return (csblob == NULL) ? NULL : csblob->csb_teamid; + return csblob_get_teamid(csblob); } /* @@ -585,8 +502,10 @@ csvnode_get_teamid(struct vnode *vp, off_t offset) return NULL; csblob = ubc_cs_blob_get(vp, -1, offset); + if (csblob == NULL) + return NULL; - return (csblob == NULL) ? NULL : csblob->csb_teamid; + return csblob_get_teamid(csblob); } /* @@ -607,6 +526,14 @@ csproc_get_platform_binary(struct proc *p) return (csblob == NULL) ? 0 : csblob->csb_platform_binary; } +int +csproc_get_platform_path(struct proc *p) +{ + struct cs_blob *csblob = csproc_get_blob(p); + + return (csblob == NULL) ? 0 : csblob->csb_platform_path; +} + /* * Function: csfg_get_platform_binary * @@ -648,6 +575,28 @@ out: return platform_binary; } +uint8_t * +csfg_get_cdhash(struct fileglob *fg, uint64_t offset, size_t *cdhash_size) +{ + vnode_t vp; + + if (FILEGLOB_DTYPE(fg) != DTYPE_VNODE) + return NULL; + + vp = (struct vnode *)fg->fg_data; + if (vp == NULL) + return NULL; + + struct cs_blob *csblob = NULL; + if ((csblob = ubc_cs_blob_get(vp, -1, offset)) == NULL) + return NULL; + + if (cdhash_size) + *cdhash_size = CS_CDHASH_LEN; + + return csblob->csb_cdhash; +} + /* * Function: csfg_get_teamid * @@ -694,6 +643,12 @@ cs_entitlement_flags(struct proc *p) return (p->p_csflags & CS_ENTITLEMENT_FLAGS); } +int +cs_restricted(struct proc *p) +{ + return (p->p_csflags & CS_RESTRICT) ? 1 : 0; +} + /* * Function: csfg_get_path * @@ -717,3 +672,100 @@ csfg_get_path(struct fileglob *fg, char *path, int *len) or an error code */ return vn_getpath(vp, path, len); } + +/* Retrieve the entitlements blob for a process. + * Returns: + * EINVAL no text vnode associated with the process + * EBADEXEC invalid code signing data + * 0 no error occurred + * + * On success, out_start and out_length will point to the + * entitlements blob if found; or will be set to NULL/zero + * if there were no entitlements. + */ + +int +cs_entitlements_blob_get(proc_t p, void **out_start, size_t *out_length) +{ + struct cs_blob *csblob; + + *out_start = NULL; + *out_length = 0; + + if (NULL == p->p_textvp) + return EINVAL; + + if ((csblob = ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff)) == NULL) + return 0; + + return csblob_get_entitlements(csblob, out_start, out_length); +} + +/* Retrieve the codesign identity for a process. + * Returns: + * NULL an error occured + * string the cs_identity + */ + +const char * +cs_identity_get(proc_t p) +{ + struct cs_blob *csblob; + + if (NULL == p->p_textvp) + return NULL; + + if ((csblob = ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff)) == NULL) + return NULL; + + return csblob_get_identity(csblob); +} + + +/* Retrieve the codesign blob for a process. + * Returns: + * EINVAL no text vnode associated with the process + * 0 no error occurred + * + * On success, out_start and out_length will point to the + * cms blob if found; or will be set to NULL/zero + * if there were no blob. + */ + +int +cs_blob_get(proc_t p, void **out_start, size_t *out_length) +{ + struct cs_blob *csblob; + + *out_start = NULL; + *out_length = 0; + + if (NULL == p->p_textvp) + return EINVAL; + + if ((csblob = ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff)) == NULL) + return 0; + + *out_start = (void *)csblob->csb_mem_kaddr; + *out_length = csblob->csb_mem_size; + + return 0; +} + +/* + * return cshash of a process, cdhash is of size CS_CDHASH_LEN + */ + +uint8_t * +cs_get_cdhash(struct proc *p) +{ + struct cs_blob *csblob; + + if (NULL == p->p_textvp) + return NULL; + + if ((csblob = ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff)) == NULL) + return NULL; + + return csblob->csb_cdhash; +}